Tom. STOP copy-pasting. Your calculations were shown incorrect in another thread.
There's nothing incorrect about those calculations. The calculations are absolutely correct. The remarks in that previous thread stem from an inability of the reader to calculate the circumference of the earth based on a difference of longitude. It's simple math, really. The earth - flat or round - will have a circumference of 360o at every latitude. If we know what the quoted distance is between the Cape of Good Hope and Melbourne we can compute that difference of 126o longitude between the two locations into 360o and come up with a figure for the circumference.
Simple as that.
Not to drag out the point, but that only works on a flat model actually. Think about it for a sec. A globe or sphere would be in cross-sections using your 360 degree method, therefore tapering into smaller and smaller circumferences as you approached the poles. * It would work either way - N/S or E/W sections.
That's my only point. I'm leaving it at that.
* Edited to add the either / or. I've noticed a tendency to comment on specifics in here so I added it in to be sure.
